Valve operating mechanism



R. c. RUSSELL lle-21,802

vALvE OPERATING MEQHANISM original Filed Aug. 19, 1932 6 sheets-sheet 1INVENTOR ROBERT c. RusaELL BY @re/ww ORNEYS May 13, 1941.

May 13, 1941. R- Q RUSSELL Re. 21,802

VALVE OPERATING MECHNISM4 Original Filed ug. 19, 1932 6 Sheets-Sheet 2 F|G.7. L F |68.

l 4 BY @lag/GU, 1'

A NEYS May 13, 1941- R. c. Russam.

I I VALVE OPERATING MECHM Original Filed Aug. 19, 19252 Sheets-Sheet 3 5f 5 .Mmm W W HH WIM mm f//yz l i; Y

May 13, 1941. R. c. RUSSELL VALVE OPERATING MECHANISM original FiledAug. 179, 1932 G Sheets-Sheet 4 INVENTOR ROBERT C RUSSELL I m m 6. G Gm.. m H WVM/NNW@ u m w w f 7 X v m l H ...ll

May 13, 1941.

R. RUSSELL VALVE OPERATING MECHANISM Original Filed Aug. 19, 1932 6Sheets-Sheet 5 INVENTOR A HUBERT G RUSSELL BY MLM ATI' RNEYS May 13,1941. R. c. RUSSELL VALVEA OPERATING MECHANI-SM v Original Filed Aug.19, 1932 6 Sheets-Sheet G H625.

l INVEN-ron ROBERT (LIPUSSELL naw ml mmm W m a:

EMM-Im ATroRNEYs Reissues May 13, 1941 t Re. 21,802l

UNITED STATES PATENT OFFICE vALvE creanme Mechanism Robert C. Russell,Cleveland, Ohio, assigner to Eaton Manufacturing .Company, Cleveland,Ohio, a corporation of Ohio Original No. 2,158,730, dated May 16, 1939,Serial No. 629,474, August 19, 1932. vApplication for reissue November29, 1940, Serial No. 367,864

(Ci. 12S- 90) 51 Claims.

This invention relates to valve operating mechanism and moreparticularly to automatic or self-adjusting and hence silent valveliijters or valve tappets for use primarily in connection with internalcombustionmotors to maintain a 11o-clearance operating engagementbetween all` parts o f said mechanism. f f It is a well known fact thatthe exact time of closing and opening the valves, inl relation to theposition of thepiston in an engine cylinder,

are importantfactors which affect the performance of the engine ormotor. IA quick opening vibration.

and quick closing valve increases.` cngine horse l powerl but has twodeilnite disadvantages, name- 1y, noisy operation andl short life forthe valve operating mechanism. On the other hand, a slowor gradualopening and closingV valve has the Atwoadvantages of being quiet inoperation and of longer life but does not afford high motor lefficiency. Even with the slow opening and closing valve, having theadvantages just' named,

great destructive forces are set up at highspeed due to the necessaryYoperating clearance between the. cam and valvemechanism now in generaluse, and this destructive tendency increases with the speed oftheengine.

Another disadvantage of conventional valve mechanisms arises fromvariations in the length `of the valvel stem or push rod and otheroperating parts. thus varying the operating clearance which is causedbyV changes in temperature.

thereby resulting in' the constantly changing consequently lowering themotor eiiiciency. A compensating, i. e., self-adjusting, valve mecha-Vtime of valve opening and closing actions, and v nisxn` whichwillconstantly maintain its operating clearance at zero or atv ano-clearance relation, despite variations in temperature and Wear ofparts, renders practical the use of. quick opening and closing valveoperating mechanism', prolongs its life Veven at high speed, and ailordsaccurately uniform and unvarying valve timing.

It'is, therefore, a general purpose of this invention, to produce novelself-adjusting or compensating valve tappetsor litters for operating thespring loaded valves, usually puppet-type valves, in relation to theirseats, as `used generally in machinery, engines and the like, and toautomatically, maintain a no4-clearance operat ing engagement orrelationship between all parts of the mechanism intermediate the engineor machine driven cam and the valve seat in the cylinder. The -inyentionpromotes operating eiiciency, improves vaivetiming, avoids impact ofparts, avoids wear and destructive hammering of the valve seats, andeliminates noise and Thevnecessity for a solution of these Problems isespecially pronounced in high speed internal combustion motors. Inaviation englues, the sqmuon of the problem .by eliminating theunusually great valve operating clearance, is

highly desirable to increase engine power, avoid valve trouble, andpromote safety. 4 The invention, therefore, seeks to produce severalpractical commercial forms of silent, automatic, self-adjusting valvelifters or tappets and which are not subjected to wear in the perform-vance of their automatic compensating or selfadjusting function. andwhich can be produced sufficiently economically to justify their generaluse.

to produce novel valve lifters capable of inherently, automaticself-adjustment or a take-up function in the length of all parts of themecha.-

v`nism for compensation in both directions, i. e..

for both contraction and expansion of the vvalve stem and associatedmembers, occasioned by temperature variation, as well as for wear atthe` bearing or engaging and contacting surfaces of all operating parts.i

A further object is to produce silent and selfadjusting valve tappets ofa solely novel hvdraulic type and which combine both hydraulic andmechanical features by.employing a novell hydro-mechanical principle ofdual aspect and jwhich functions in conjunction with a small volume ofoil under light pressure land confined in a variable size liquid o rhydraulic compensating chamber which increases or decreases in volume to@neet wesen-adjusting nmcuon and thus Y maintains the valve operatingmechanism in a self-adjusted zero-clearance state.

In an hydraulic' valve lifter it is important that the inilow yof liquidsuch as oil into the compensating chamber should respond quickly to theslightest compensating movement of the self-adjusting elements, butwhere it is sought to yuse a spring .to seat the tappet control valve,the

inilow of oil is retarded and thus sensitivity is lost, inasmuch as thespring must iirst be compressed. I find that the control valve for the Ysmall volume hydraulic lifting chamber should be entirely free of springmeans and only urged to its seat by'gravity,or by the up stroke of the'tappet to open the engine valve, or by the pressure in the hydraulicchamber, and certainly not by a spring.V It is an object oi' thisinvention Vto producea valve lifter meeting 4the conditions by which toattain quick priming of the keepingV with these purposes.' it is myobject' hydraulic chamber and instantly added increments of oil tocompensate for the slightest contracting of any operating parts.

It is also found that a free circulation of oil should be provided in ahydraulic tappet, since to compress thesame body of oil an infinitenumber of times causes the oil to become aerated and emulsified into adeteriorated thin jellylike mass and when inthis state it is no' longernon-compressible and loses its capacity -to actuate the engine valveagainst its stiff closing spring. Serious defects with hydraulic tappetshave lbeen caused by air soaked oil which is a condition found dimcultto overcome because at high engine speed the tappet reciprocatesveryrapidly which violently churns and emulsiiles the oil, more esDei ciallyso when the oil is under great vpressure as indeed it is when liftingthe valve against its closing spring unless a great .portionfof the loadorpressure offtliat spring is`.f`e liminated. The supply of oilavailable for the compensating hydraulic chamber should be fed and bledso that the supply is of fresh oilfat all times, otherwise the rapidreciprocation ofthe tappet will churn and render said oil supply uselessas a non-compressible body and would fail as such if drawn into thecompensating chamber and wou'ldnot force against the heel of the valveoperating cam,

wherebyl my novel deviceavoids undue friction and wearagainst said camduring the period the valve is'on its seat. Therefore, the oamiollowersof my tappets have a period of rest and wear'is minimized due to thereduced bearing friction on the heel of the cam.

Another object is to produce a valve lifter having novel overlyingself-adjusting wedge means conned within a guide chamber and definingtlierein'the compensating hydraulic lift chamber tran-smit the throw ofthe camto open the engine i valve. Each valve-opening movement of thetappet should tend to force new oil to the supply receptacle adjacent toand available for feeding l the smaller hydraulic compensating liftingchamber andthe old oil should pass out through an overilow back to theengine crank case.v These desirable features, I now attain by a simplecon- A struction of iewv parts and without Special oil pipe leads andwithout pressure supply lines or y complicated tubing or piping.

A further object of the invention is to produce |a valve lifter whereinthe hydraulic compensating means or self-adjusting unit per se actuatesthrough a. greater distance than the'corresponding variation or changein length of the valve operating parts, and this results in providing alow compression hydraulic chamber with minimum tendency to force out orlose its oil when opening the .engine valve. In other words, the

compensators per se in my invention have a proportionately greatertravel (say several thousandths of an inch) in maintaining thezeroclearance function, than the movement or change in length (say onlyone. thousandth of an inch) of the valve stem or push rod and otherparts constituting the engine valve operating. mechanism. Thischaracteristic function of my invention produces a quick opening of thecompensating oi-l chamber control valve for the slightest variationinlength of the valve'mechanism and draws a comparatively large volumeof fresh oil into said chamber for a relatively small variation' inlength oi operating parts. Thus by amplifying orV greatly increasing.the compensating movement of the self-adiusting means, relatively tothe-shorter change in length of the valve stem and other parts, arapidly :till-ing and self-priming tappet is-produced. Thus, while inoperation, if the oil supply should fail or run low, or if forsome'causethe hydraulic chamber should ldrain due to long non-use of theengine, the valve lifterV will function as a conventional tappet withoutserious harmf and when the engine is started or the oil supply is againavailable the tappet will immediately pick up oil by sucking it in andresume its functionas a compensating device. This feature is also agreat advantage in assembling vbut it lifts only a small per cent' ofvthe -valve load. In this way is attained a characteristic andnoteworthy reduction of pressure on the oil in the hydrauliccompensating chamber to minimize the tendency of the oil to emulsifytherein and also avoid loss of oil from the chamber when lifting theengine valve oil' its seat. In this connection, I really employ thehydraulic chamber, the oil therein, to lock or hold apart the wedges intheir precisely self-adjusted position, whereas the thrust or great loadof the cam Iand engine valve spring isA carried' directly through thecoacting wedge faces which are restrained from slipping or displacementby the sealed incompressible oil body between the wedges.

Another object is to produce hydraulic valve l lifter compensatinginstrumentalities including means acting to positively expel the air, ora maximum portion thereof, from the hydraulic' Pursuant to the foregoing`.air-*expelling funcnon, it is a. further object of this invention toproduce a hydraulic 'valve operating device having maximum displacementmeans by which the volume of the hydraulic compression vchamber isreduced to zero or to a minimum spaced. e., Q minute in volumetriccapacity '(or the 'chamber .i entirely closesor disappears for completedis--flv u placement), upon the iirst turn ofthe engine cam, preliminaryto sucking a chargent oilinto the maximum displacement oil chamber, andin this way the air is initially expelled fromthe vhydraulic compressionchamber and thus said chamber is conditionedto receive and retain asolid body of air-free oil. In this "Mv is minimized the likelihood ofthe oil becoming air bound or locked, 4aerated and emulsied, and

hence Lprevent the hydraulic oil body from losi ing its incompressiblecharacteristics.

The foregoing object, i. e. the attainment of maximum displacement forthe hydraulic chamber, can of course be carried out with either a largeor small volume hydraulic chamber. I have, however, illustrated myinvention with a reduced size or minimum volume compression chamber ofmy maximum-displacement type, the object ,being to operate theself-adjusting unit in the device on a comparatively small oil body andthus lmake use of a minimum of aerated oil in any event should there bea tendency toward the presence of air.

A still further object is to produce a hydraulic 4tappet having acomparatively small volume compression chamber in combination with asubstantially large size non-draining Yoil receptacle or supply, theinlet or feed leading into the latthe tappet expanded-to compensate foracon' fork having its lifting stem and guide'head which slidably fits inthe upper endof the tappet sleeve to enclose the parts named;

Figure 7 is an assembly view of the valve operating mechanism with thehydraulic vaivelifter interposed between the spring loaded valve stemand the engine cam, and this view .shows tracted valve stem, asindicated by the reference line X;

Figure 8 is a view similar to Figure 7 except that Athe self-adjustingparts have automatically contracted into the tappet sleeve toaccommodate a somewhat elongated valve stem, as shown ter being locatedhigh above the bottom wall lof said non-drainable receptacle, and theoutlet leading from said non-drain receptacle into the small hydraulicchamber being located near the bottom wall of said receptacle.

Also it is an objectto produce a hydraulic dro-mechanical features, asfollows:

'I'he first form of the invention is illustrated in Figures 1 thru 8 andwhich I have sometimes referred to as the fork and wedge type ofhydraulic valve lifter.`

Figure 1 shows a vlongitudinal section thru va fragmentary portion of atypical internal cornbustion-engine having poppet type valves and inconjunction with which I have illustrated my in ventlon;

Figure 2 shows a longitudinal section thru the valve lifter or tappet astakenon the line 2 2 of Figure 1, on an enlarged scale, and removed fromits guide in the engine base:

Figure 3 is a cross-section on the line 3-7-3 of Figure 1, with thetappet also removed from its guide in the engine base;

Figure 4 is a cross-section on the line 4 4 of Y vFigure 1, but with theupper one piece double face or fork type compensating wedge memberremoved from the tappet sleeve; Y

Figure 5 is a perspective view of a wedge seat or retaining and'gtuidemeans therefor, as, removed from the tappet sleeve, and within which theself-adjusting wedge means is carried tov form a compensating hydrauliclifting chamber, and this member also carries the characteristicnon-spring closed control valve which admits oil intohydrauliccompensating chamber;

VFigure 6 is a cluster or exploded view of the tappet parts removed fromthe lifter sleeve and disposed in aligned order of assembly, showing theparts, reading from the bottomv unto-wit, the

cam follower tappet sleeve, the wedge seat, a ball valve, a compensatingspring, the self-adjusting wedge pair, and the overlying double facedwedge sov ' automatic compensating means embodying hyby the referenceline Y. The range of several thousandths of an inch variationin lengthof operating parts is thus diagrammatically shown at XY;

ond form shows an enlarged non-draining underneath oil supply chamber orreceptacle below the hydraulic compensating chamber and which alwayspOsitively insures a full flow of fresh oil to theA hydraulic chamberformed by the 'selfadjusting wedges even though the engine has stoodidle for a long period andthe oil drained away from many of the engineand valve parts. 'Ihis form of the invention also provides meansforoiling the cam from the overow of oil issuing from the non-drainingtapp'et supply receptacle as an incident to keeping the oil freshlychanged inthe supply receptacle beneath the compensating chamber.

Figure 9 shows a perspective view of a compensating wedge means retainedguide or wedge seat having an o il intake neck 'to project down into thenon-draining fresh oil supply chamber 'and adapted to convey oil to thecompensating -hydraulic chamber formed in said guide by the yWedgemeans, but with the latter removed;

Figure l0 shows a cluster view of this second form of valve liftercompensating mechanism spread apart in order of assembly;

Figures 11 and 12 are comparative assembly views of an engine cam andspring loaded valve with the hydraulic lifter interposed therebetween,

Figure 11 showing the lifter automatically expanded and Figure 12contracted to maintain a no-clearance engagement in respect to allparts' ofA a conventional valve operating mechanism.

. 'I'he reference lines X and Yshow the range of automatic compensationin these two views.

` A third form of the invention is shown in Figures 13 through 18 whichillustrate a hydraulic valve lifter embodying a modified form ofcompensating wedge means of reduced number of parts comprising an upperand lower wedge means each of which has a double acting face.

Figure 13 is a cluster viewof the third form showing the compensatingmechanism removed .of Figure 14 with a push rod omitted and the liftersleeve removed from its guide in the engine base;

Figure 18 is a cross-section on-the line I8-I8 .of Figure 14 with theupper compensating wedge and push rod removed and looking down on. afreely movable ball valve which controls the inlet to the hydraulicself-adjusting chamber. v

A fourth example of the invention is shown in Figures 19 through 23 andmightbe referred to as the screw jaw type of self-adjusting hydraulicvalve tappet.

Figure 19 is a. cluster view with the compensating parts withdrawn fromthe tappet sleeve and spaced apart in their order of assembly;

Figures 20 and 21 are valve and cam assembly comparative views showingexpanded and contracted positions of the valve `lifter to accommodate acontracted valve stem as in Figure 20 and an elongated valve stem as inFigure 21. The spaced reference lines X and Y point out thisrelationship and shows how the automatic 'device maintains itsno-clearance engagement between the cam and valve stem throughout the XYrange of variation in length of parts;

Figure 22 is a cross-section on the line 22-22 of Figure 20 .but withthe upper self-adjusting screw jaw or wedge means removed, from thetappet sleeve to expose the wedge faces of the lower stationary member;v

Figure 23 is 4a cross-section on the line. 23-23 of Figure 20illustrating the two spring means tending to expand the valve lifter byrotating the two screw jaw compensators.'

' end forming a cam follower I3.

A ilfth example of construction is illustratedl in Figures 24 through 28and which also comprises a hydro-controlled triple mechanical wedgemeans designed to compensate for all variations in length of the valveoperating mechanism, and wherein the hydraulic chamber isl remote fromthe wedge means.

Figure 24 shows the compensating parts in spaced alignment in the orderof their assembly and withdrawn from the'tappet sleeve;

Figures 25 and 26 illustrate comparative position and assembly viewswith the hydraulic valve lifter interposed between the engine cam and,spring loaded valve, and the reference lines Xv and Y indicate,respectively, the valve lifter in its expanded and contracted positionsto compensateforcontracted and expanded valve stem conditions; l

Figures-:27 and 28 illustrate sections on the lines 21 and 28 of Figure25 with the lifter removed from its guide in the crank case of theengine.

The first ,form of construction in Figures 1 through 8 In illustratingthe several forms of my selfv the usual kind includes a valve head 5adapted to open and close in relation to its seat 4 and an integralvalve stem 6 reciprocates in its guide structions also include a tappetor valve lifter` guide II. in which a valve lifter is mounted betweenthe cam 9 and tail end of the valve stem 6.

The foregoing is exemplary of standard engine practice. i

I flare or cup the upper cylindrical end of the guide II to catch` oilfrom the splash lubrication system or other oiling means of an engineand by which to feed oil down into the valve lifter. In the presentinstance my invention includes a lifter or tappet sleeve I2 having alower closed In operation, my valve lifter I2 transmits the throw orthrust of the cam lobe I0 to the spring loaded valve 6 to lift the sameagainst the expanding closing force of the engine valve spring 8. Inconventional practice, there is always left a few thousandths of an inchclearance between the old form oftappet in the guide il and the end ofthe valve stem 6 Ato allow for expansion and contraction due totemperature variations, but in my invention this space is constantlyclosed throughout all ranges of length change in the valve stem andother mechanism.

My invention, among other things, comprises a combination hydraulic andmechanical self-adjusting means carried' in the tappet sleeve I2 fortransmitting the thrust and carrying the load generated by the valveclosing'spring 8 and valve. opening cam lobe I0. The valve lifter sleeveI2 has external oil grooves I4 extending longitudinally from the upperopen end of the sleeve and communicating with a circumferential groovecontaining holes I5 thru the sleeve wall. This construction provides asystem of passages which convey oil from the upper flared portion of thetappet guide II of the engine to the inside of the' tappet sleeve tofeed the compensating mecha- .transversely Aat I8 to form a. system ofoil leads to the underneath portion of this wedge seat device IS, Thiswedge seat IG has an outside diameter adapting it to a, sliding t intoand a stationary position at the bottom of the sleeve .I2 and hence onthe cam follower I 3. The oil grooves I1 and I8 convey oilfrom thesleeve passages I4 and I 5 downwardly along the inner surface of thetappet sleeve I2 to the very bottom or underneath portion of the wedgeseat IG.

'I'he plug-like wedge seat I6 is further characterized by a rectangularopening or chamber-ing slot 2i cutfrom its upper end and extendingdownwardly and forming a. fiat bottom slide surface 22 formed at anangle to the engine-valve stem 6, say at right angles thereto. Acompensating or self-adjusting pair of plunger-like wedges are slidablymountedupon the flat seat 22,.and also within the slotted opening 2|there is formed a hydraulic compensating chamber of variable capacity aswill be described. A valve controlled inlet and valve seat 23 is madecentrally through the flat bottom wedge seat 22 and connects with thetransverse oil grooves I8 to receive oil from the sleeve grooves Il andflared guide i I. The inlet 23 includes a valve seat on which a freely s21,802 movable ball check or other form of valve 24 tion of all thesefactors.k Purposely, no springFV means is employed to close thiscompensating ball valve means -2li and hence its action is sensitive andquickly responsive. to un unseating tendency to allow oil to pass theseat 23 and iiow upwardlyV into the slot 2I and a hydraulic chamberformed therein, as will be explained. The wedge seat member I6 restswithin the sleeve, is stationary therein, and reciprocates therewith.

A self-adjusting plunger means in the form of a wedge pair, comprisingtwo symmetrically formed wedges 21 and 28,.in the nature of rectangularfaced plungers, having flat bottoms 28, are spaced apart with acompensating spring 30 mounted therebetween with the spring ends seatedin a socket 3I made in the adjacent faces of said wedges. Th wedge pairV21, 28 has its lower flat faces slidably seated on the surface plane 22with one wedge placed to either side of the oil inlet 23 and theexpansion of the compensating spring 3Ilv tends to thrust the wedgesapart in the performance of their compensating function in onedivrection'to automatically adjust outwardly for a contracting valvestem 6, as at the reference line X, yet this spring 3D yields to affordthe reverse compensating function to adjust inwardly for an elongatingvalve stem 6, as at the reference line A Y. The wedges 21 and 28 have asubstantial range of transverse movement at right angles to the' axis ofthe member I6 and its carrier sleeve I2. The

Y limit of their outward movement is defined by the wedges abuttingagain'st the inner wall of the sleeve I2 and` the'limit of their inwardmovement is substantially a dead center position, as in Figure 8, wherethe wedges have practically closed together and compressed theself-adjusting spring means'3. Thus a double positive stop is providedfor the self-adjusting plunger means 21, 28.

sleeve I2. In other words, the outer vertical faces f of the two wingsforming the two-faced wedge 33, arecylindrical in form, similar to thehead 30, and have aguided fit in the sleeve I2 the same asthe head 35.The wedge member 33 has a verticalr oil groove 31 made in each outervertical'cy'lindri;r

cal face to lead oil down to the bottom of the,4

wedge seat I6;

The adjacent parallel or vertical facesA of the two-spacedself-adjusting wedges 21 and 23, to-

gethe'r with theupper converging wedged faces l 3B of the member 33, aswell as the lower flat face 22, taken all together define or set Off aclosed hydraulic compensating chamber 4 0 of small volume with maximumdisplacement. and of generally rectangular shape, as shown in theassembly views and which varies in size and volume to compensate forcontraction and expansion of valve stem E and other parts of the valveoperating mechanism. The flat vertical faces 'of all three cooperatingwedges 21, 2B and 33 have, a close sliding plunger-like or piston fitwithinvthe parallel walls forming the slotted opening 2I in the wedgeseat I6.

28 and 33, constitute in effect a three-part plunger A one-piecedouble-faced wedge member or pilot wedge 33 is carried on the lower endof a thrust post orstem 34 having an upper guide head 35 slidablyconfined in the upper end of the sleeve I2 to close the latter. Thissingle wedge 33 is made -with'angular or forked 'wing portionsoperatively ydisposed in the upper end of the slot 2| of the wedge seatI6 and embracing or coacting with the lower wedge pair 21, 28. The threewedge elements have symmetrically coacting angular or wedge faces 36which cooperate to form an automatic selfadjusting unit within theslotted charn-V ber 2| of thewedge seat I6. The single spreadingdouble-faced wedge 33 includes the two con- '.verging wedge faces 36,meetingor converging g 4centrally at an apex coincident with the axis ofthestem 34 and lifter sleeve I2. The compensating spring 30 tends todrive the two self-adjusting wedges 21 and 2B outwardly, thus slidingthe coacting wedge faces 36 along the double faced wedge member 33, andthereby urging the latter upward :and longitudinally or outwardly of thelifter sleeve I2. Down Apressure of the forked wedge 33, caused by theheavy valve spring 8, sets up a resultant closing force against thewedge pair 21 and 28 tending to actuate them centrally and toward eachother to slide them to the apex of the slotted member I6. The one-piecedouble faced wedge 33 is adapted to an up and down sliding movement inthe chambering slot 2 I, while the two symmetrical wedges 21 and 28 areladapted to undergo a. transverse sliding movement atright s angles tothe axis of the sleeve I2 and stem 34 throughout the operative slidingaction df all three wedge means, they maintain a close oil tight fitagainst the walls of the member I6, and function in effect like a pistonin a cylinder Yexcept here are employed flat slidingIsur'faces insteadof cylindrical surfaces. i

' The component parts of the self-adjusting hydraulic valve lifter, asshown in Figure 6, re mounted in the sleeve I2 as shown in the assem ylyviews, and the outer cylindrical surfaces vof the wedge `33 have a freesliding t in the inside cylindrical surface ofthe sleeve I2 and likewisefor the outer small cylindrical face on leach-compensating wedge 21 and2B. When assembled the compensating spring 30 keeps the wedges 21 and 28spread apart under the single wedge 33 and thus bears the stem 34 andhead 35 upwardly against the lower end of the valve stem i to maintain a`zero-clearance relation therewith- The parts are stand apart determinesthe low or small volumetric capacity of the valve controlledh'ydrauliccompensating and lifting chamber 43 and, as the wedges move farther'4apart.'l they enlarge this chamber and thus produce a suction Atl'iereinwith the result that the ball valve 24 is sensitively' lifted off its`seat and fresh oil flows up into the chamber 40, whereupon the ball 24again seats and entraps the oil in the chamber 4l, thereby locking orpositively holding said wedges apart to f fuliillv their function ofraising and lowering the The compensating `wedge set, comprising thethree self-adjusting members 21,

,i angle the less pressure.

an angle approximately as shown in'" order to spring loaded valve inrelation to its seat i against the powerful closing force of the enginevalve spring 8.

'I'he ooacting wedge angles or inclined planes at 36 are comparativelyfiat. The steeper the angle, the more pressure there would be exerted onthe hydraulic chamber 40 by the sliding reaction of the wedges.

Consequently, I choose exert a minimum of pressure onthe oil chamber iiiand yet an angle sufficiently steep to permit a retractin'g orapproaching movement of the wedges 21 or 28 under the force or" theheavy valve closing spring 8, vwhich occurs when the valve stem 6expands due to arise in temperature conditions. -An angle in theneighborhood of twenty to twenty-live degrees, as measured from t thehorizontal or aline drawn at right angles to the line of thrust or axisof the valve stem ii, is shown and gives satisfactory results. Thisangle may be varied somewhat and can he increased or made steeper sincethe oil in the hydraulic chamber 40 will positively hold the wedgesapart to lift the valve 5 and compress its spring il.

Conversely the flatter the The inclined thrusting and self-adjustingsurfaces 36 in the compensator unit are found te give very satisfactoryoperating results with approximately the angular measurement hereindis..

closed. As an example of the comparatively low pressure exerted on theoil in the hydraulic chainber 40, let us assume that it requires athrust of 125 pounds to actuate the engine valve 5 in rele.- tion to itsseat 4. 'I'he angular wedge means here disclosed will only transmitabout 3 per cent of the load pressure to the oil in the hydraulicchamber. Hence conventional valve springs of 125 pounds compression'alresistance would only subject the oil to a pressure of 3.75 pounds, butinasmuch a's the spring 30 will easily carry part of this load, say 2 or3 pounds pressure, it is easily seen that only 1.75 or .75 poundspressure is ultimately 4applied against the oil in the hydraulicchamber. In other words, the oil has to stand only 1 or 2 poundspressure to hold the wedges 21 and 28 apart while they compress the 125pound engine valve spring 8.

Inv the nrst form of the invention thes'upply of oil for the hydraulicchamber 40 flows down thru the sleeve grooves I4 and enters the insideof the tappet sleeve I2 thru the circumferential groove -and passagemeans -I5, and thence the oil feeds down thru the groovesA 31, I1, I8and then up thru the valve controlled inlet 23 leading to the hydraulicchamber 40. To insure a free ow of oil along these passages, it ispreferable to provide vent holes 4I in thellifter head 35 and its stem3@ so as to equalize the air pressure in the sleeve under the head toavoid all possibility of an air lock in. order that the oil may runfreely down thru the passages and stand available at the ball checkvalve 24 to be admitted to the chamber Ml upon the slightest outwardmovement 'of thewedges 21 and 28 under the expansive force of the spring30. ,In other words, the open spaces lin vthe sleeve are under normalatmospheric pressure the chamber 46, due to the preferably restrictedsize yof the latter, merely serves to keep the plunger wedges apart andsubstantially all of the thrust delivered from the cam lobe I6 istransmitted thru the coacting Wedge faces 36 of the compensator unit,Whereas, only a small percentage of the load is exerted in the form ofpressure against the oil in the compensating chamber stil. Hence thereexists little or no tendency to emulsify the oil because it is notpounded and compressed by the `continuously running cam lobe iii. Theupward thrust to open the engine valve 5 as Well as the downwardpressure te' close it, is substantially and largely carried on, at orthru the engaged wedge faces made at an angle between fifteen or twentyand say thirty degrees. By eliminating the continuous pounding andminimizing the pressure ori-the small body of oil in the hydrauliclifting chamber dii, it follows that the oil is not air soaked andemulsiied into a thin jelly-like substance to lose its capacity as anlli-compressible agent to positively hold the wedges 21 and 2 apart, andconsequently the Wedges perform their function perfectly and do not slipon their seat 22 'during normal operation when no compensation isrequired due to constant engine temperature conditions.

Ari important structuralfeature which contributes to the successfuloperation of several forms of my invention resides in the fact that theself-adjusting wedge pair 21, 2S has a long range of travel and ismultiplied in fact many times over the shorter travel of the singlewedge 33. attain this characteristic by the ratio -wedge means.I It isapparent that the angle E@ `compels an outward sliding or separatingmoveber in larger measures, many times over, and the ball valve unseatsand there occurs a substantial intake of oil, increments which could notbe added to the oil already in the chamber except for my amplificationof the self-adjusting action greatly in excess of the slight change inlength of operating parts. 'This feature also makes for quick'primingand ypositive filling of the hydrau- I lic chamberwhen the mechanism isfirst installed. It is also noteworthy that there exists a minimum offrictional pressure between the cam heel 8 and the cam follower I3during the period the valve head 5 is on its seat 4. This mode ofoperation follows by reason of the fact that the selfadjusting orcompensating spring 30 is comparatively light, but more particularlybecause its expansive force is absorbed ortaken up and resisted.-vsomewhat by the coactlng angular wedge faces 36. By the time theself-adjusting spring '30 expends its force'thru the wedge faces, thereis comparatively little reaction pressure from this spring transmittedto the cam heel 9, Hence the cam 9 is rested soto speak and relieved ofundue wearing pressure during the time the heel traverses said cam withthe result .that heat and friction is reduced between the bearing faceof the cam 9 and follower I3 .with the result that oil more readily ndsits way to these engaging .surfaces so that the Wear of these parts is'mini-` mized.

When the valve lifter is flrst assembled, it is dry, i. e., its smallchamber 48 contains no oil.

l The first turn of the cam I .causes the plungers 21 and 28 toreciprocate toward each other and vclose up with their adjacent verticalfaces coming together. VThis action displaces or completely eliminatesthe hydraulic chamber and consequently displaces all-air therefrom or a`maxi-l mum portion thereof. By'ths maximum displacement function, allair is expelled from the compression chamber. Also thel action of theplungers 21 and 28 coming together provides a stop or inward travellimit to' prevent over-compensation in one direction, i.,e., preventscon` traction of the self-adjusting unit into its tappet body or sleeveI2. As vthe cam I0. continues to turn and its heel 9 engages thecamlfollower I3, the return or compensating spring 38 beginsto Vexpandand thereby separates the wedges 21 and 28,v thus sucking oil past theball check 24 into `the air-free hydraulic chamber 48. The tappet has anAoutward limit of compensating travel for the plunger lmeans 21, 28 byvirtue of the outer end of each plunger coming into engagement with theinside wall of the sleeve I2, and thereby the'self-adjusting unit islimited as to its over-compensation in the other direction, i. e.,

expansion outwardly of the sleeve I2. The small volumev of oil .nowtrapped in the compression chamber locks the plunger wedges apart incompensated position, whereby said plungers transmit therlift of the camlobe at the next and all successive turns of the cam. g

The small volumetric capacityof'the compen,-'v

sating chamber 4l| simply means that thesmaller the amount of oilcontained therein the smaller will be the amount of air occluded in theoil and the less will be the gas or bubbles liberated by the oil when itbecomes heated and is working under pressure. It is appreciatedtherefore that the small volume chamber l4l), coupled with the fact thatthis chamber is capable of complete or maximum displacement, constitutesimportant features of construction and operation in my invention'. Thisprinciple, by which I have solved-certain preblems which heretoforecaused failure of long sustained-operation of hydraulic valve lifters,is also shown or employed in the design, construction and-operation ofmodifiedA -forms of my invention,

A description will now be made of the other forms of the invention, butin doing so the reader will take into account the above description ofthe first form inasmuch as many explanations already given apply ineffect to the succeeding heretofore used, are applied to theconventional engine parts, such as the spring loaded valve, itsoperating cam, and other standard parts.

A tappet sleeve 42 is very similar to the former lifter sleeve I2 andhas a closed bottom 43 as a cam follower and an open upper end toreceive a compensating unit to be described. vThis sleeve 42 is designedto positively retain a substantially large supply of fresh oil in itslower end and in this connection there are made a number of oil holes 44thru the sleeve high above the bottom end 43 thereof and within acircumferential groove 45, thus providing a deep non-draining oilreceptacle 48 in the sleeve. Longitudinal oil feed grooves 46 are cutexternally inthe sleeve from the top end downward and communicatel oilfrom Vtime to time. In this way, there is always provided a largerinflow of oil to the nondrain deep receptacle 48 than is afforded by thedischarge passage 41 of less conveying capacity than the several feedpassages 4B. The recipro-l I eating action of the sleeveV 42 effectscirculation of oil therethru to keep the supply fresh. Any

suitable means may be used to feed oil into the `oil inlet 44 placedhighin the sleeve 42.

'I'he lifter sleeve 42 is made with a slightly larger upper internalbore than the lower portion which forms an annular shoulder means 49above the oil feed passages 44 and 45 and which f acts as a rest orsupport for awedge seat member 5I, shown in Figure 9, and whichclosesthe upper end o'f the non-drain oil receptacle 48.

spo

forms and for that reason certain established principles and modes Vofoperation may hereinafter beonly brieiiy recounted or even omitted wherethe same are common to the types of valve lifters hereinafter,described.' f

The second form of construction in Figures 9 thru 12 v l ln this speciesof the invention, the same selfadjusting or compensating means per se isemv ployed las heretofore described, but a characteristically differentmeans of fresh oil supply is afforded the small-volumemaximum-displacement hydraulic chamber, by way of a larger and morecertain supply, which is always maintained, no matter how lons an enginestands idle to afford opportunities for al1 the oil to' drain away fromthe parts.' The same reference characters as' This wedge guide retainerseat 5I is similar in function to the rst described wedge seat shown inFigure 5, but is structurally different in that a long oil inlet neck ortube 52 `reaches from the plug portion 5I down to the bottom of thenondrain oil receptacle 48.` 'Ihe neck 52has its upper end integrallyformed or otherwise secured 52 projects down into the oil receptacle 48.A

.freely movable ball check valve 55 rests on the seat 53 and normallycloses this oil inlet to admit oil up thru the neck 52 but prevents areverse ow thereof. The lower end'of the tube 52 is always immersed inoil no matter how long an engine stands unused, because the oil supplyreservoir 48 never drains. The member 5I comprises-in eii'ect, apartition which divides the tappt body or sleeve into a large oilreservoir orl receptacle adjacent a small compensating space into whichis operatively mounted the selfadjusting unit. Y

A pair of automatic self-adjusting wedges 51 havey flat bottoms whichslidably rest on the hat upper surface at the bottom of the channel orchamber 54 in the wedge seat 5i. /A compensating spring Il is disposedbetween the wedge pail l? with the spring ends inserted in a, socketformed in the adjacent face of each wedge and keeps the wedges urgedapart. This spring Sii rests horizontally right above the bali valve 55and serves to prevent it from falling out oi place during assemblyoperations or during high speed reciprocation of the tappet in event oilhas not yet become entrapped in the hydraulic chamber above the ballvalve e5.

Next in the assembly, there is provided s. single or pilot wedge tehaving wing means and a double wedge face symmetrically formed in respect to the two wedges E? and embracing or forkingr over the latter.This double faced wedge 59 rests on top of the two wedges 5l within theslot 5t? of the seat and wedge retainer plug 5i. The outer surfaces ofthe winged wedge 5% have a cylindrical bearing and sliding fit insidethe sleeve 42 and its parallel flat sides have e. close oil tightsliding t between the parallel at walls defining the wedge slot orchamber` 5t. Thus is constituted a hydraulic smal volume compensatingchamber 80 (see Figure 11) formed by the underneath convergingwedgesurface of the member 59 which constitutes the top closure of thechamber 80,. the ball valve 55 and wedge seat 5i' forms the bottomclosure, and finally the ad-4 jacent parallel shorter flat faces of thetwo selfadjusting wedges' 5i form the other closure walls of this,chamber 8?. The spring 6E is transa versely disposed in the chamber ilover the bali valve E@ and out of engagement therewith to leave it freeon its seat 55S. The wedge it constitutes a valve thrust member toliftthe engine valve t: and a seat against which the tail endoisaid`valve stem rests with rio-clearance engagement therewith.

The' foregoing self-adjusting parts or compensator per se, comprisingthe wedge seat 5i' ton gether with the double faced wedge 5t and-intermediate parts, are mounted in the upper end of the sleeve 42 andanchored on its shoulder 4t.V

The automatic tappet is now complete and ready, to be inserted in thetappet guide Si usuallyformedl in the crank case oi" an engine. Theself-adjusting parts in the sleeve automatically assume a zero orno-clearance engagement between the engine valve 6 and lifter wedge 59for 'the reason that the 'compensating spring E@ thrusts outwardly onthetwo wedges il. thereby moving wedge 59 upwardly until it'seatspositively against the lower end of valve stem 6. The weight of thesleeve and'expansive force of the spring 5l act downwardly on the sleevel2 to maintain its cam follower ll in no-clearance engagement with thecam. Hence the entire valve mechanism is set up without the slightestplay,

beginning with the running surface of the cam and extending all the wayto the face of the valve seat l throughout all the mechanism..

In operation, oil is supplied in any suitable manner tothe inlets I4 orcollects around the upper cylindrical end of the engine tappet guideIl', from rother' parts of the engine such as the crank case, and ilowsdownward along the grooves' 46 and thru the holes to illl the oilreceptacle I8, When this receptacle is filled, the overflow oildischarges outwardly along Athe groove I1 and pours directly upon'thecam 9, Ill to keep it lubricated. It is noteworthy that the lubricationof the cam from the receptacle ,4l

thru the oil drain groove 1 is very effective because the cam heel isunder light pressure and thus readily retains oil to lubricate the lobei0. The self-adjusting spring. 58 is comparatively light and the wedgemeans resists its-expansive force and the cam follower end 43 bearslightly on the heel 9. The oil supply never completely drains from` therebeptacle and, inasmuch as the supply neck 52 dips into the lowerportion of lreceptacle 48, it is apparent that there is always availablea supply of oil to feed upwardly thru the neck into the hydraulicchamber 6G.

'I'he rotation of the cam I [l thrusts up-4 wardly thru'the liftersleeve 42, through'the shoulder dfi, through the wedge assembly, into`the valve stem 6 and thus lifts the engine valve 5 ofi its seat 4 bycompressing the engine valve spring 8 which resiliently loads the valvei to keep it closed on its seat and maintains the sleeve i2 against theface of the cam as the lobel i@ the space 5 6, quickly fills thehydraulic chamber 'forced in by atmospheric pressure.

6@ with oil by suction. The ball check valve 55 is sensitive to theupward inflow of oil drawn thereinto by suction of the plunger wedges 5lor Instantly the chamber 60 is filled with oil, there remains no vmorelost motion ibetwe'en the cam follower 43 and its driving cam or betweenthefvalve'stem 6 and its wedge 5, and the device is set for conetantoperation.

An angle suflciently steep is chosen for the oo acting wedges 5l and 59,as already expl'ained'in the first form of the invention, whicheffectively reacts thru the incline planes of the three wedges 5l' and59 to slide the piston wedges 5l' together in event no oil is entrappedin the chamber 60 'formed therebetween. 'I'helr next outward strokeprimes or fills the chamber Bt. This angle is not made too steep forthat would place too great 'a pressure on the oil in the chamber 6G. Onthe other hand, theangle is properly designed as not being too flatbecause it is desired that the wedge pair 51 have considerable relativemotion along the fiat bottom surface of the seat 5l in event no oil isin the hydraulic chamber 60 by which to pump oil up into that chamber.In other words, an angle somewhere between 15 or 18 to,25 or 35degrees', measured from the horizontal, may be used but the angle shownof approximately 22 to 24 degrees, or threabouts, gives verysatisfactory operation, and ,affords the wedge pair 51 a proportionatelygreater self-adjusting movement than the shorter variation in length ofthe valve Istem i and other partsdue to changes in tem- Derature.

In event the valve stem 6 gradually shortens, as in Figure 1l by coolingoft, the compensating spring 58 gradually thrusts the wedges 5I apart,

moving them several thousandths of an inch more than the valve stemGxcontracts, thereby drawing oil from the supply receptacle 48 upwardlythru the tube 52 into the chamber 60 to keep the wedges 51 hydraulicallylocked in their outermost self-adjusted position. As the lobe I0 thrustsupwardly on the sleeve (2, the pressure or force 21,802 is comparativelylight on the oil in the chamber En because most ofthe thrust is carriedthruthe wedge pair to the valve stem engaging wedge 59. The plungerwedges have outer stop means to limit their self-adjusting movement inthat the outer end of said wedges come to rest against the innercylindrical wall of the sleeve 42.

On the other hand, 'should the valve stem 6 elongate, as in Figure 12,then the powerful force of the valve closing spring 8, acting thru theinclined plane of the self-adjusting wedge means, i. e., thewedge 59bearing heavily on the two slidable wedges 51, causes the latter toslidably approach each other sinceA the closing force of the spring 8 issuflicient to enforce acreeping approach movement of the two wedges 51by com- -pressing the yieldable spring 58. The two plungers 51 have aninward travel limit or stop function when they meet at the apex of thepilot wedge 59. f course, the closing or approach action of theadjusting wedges 51 is resisted by the oil in the chamber 60 but theincreased pressure thereon becomes so great, due to the graduallyincreasing length of the valve stem 6, that the oil leaks out of the'chamber 60 along the Asides of the wedges or even past the ball valve.

In fact it is not necessary to make the wedge set 51 and 59 with such aclose and tight lit in the seat Bland its channel 54 that no liquid canescape from the chamber GII since theviscosity of the oil retards itsescape. Furthermore, the

engine valve opening and closing action by the cam III is so rapid thatno appreciable amount of oil has time to escape from the .chamber GIIduring any one valve opening action,'and for the further reason thatlittle force or pressure is normally applied to the hydraulic 'chamberdue to the are eliminated and the incompressible characteristic of theoli is preserved. These features.

small-volume and maximum-displacement compression chamber, are importantprinciples in my invention. v

Y The third fbrm cf construction in Figuresvrs thru 1s This form of theinvention is similar in principle but modied in structure over thespecies `heretofore described and I have shown it in connection with anoverhead rocker arm type of valve operating mechanism for valve in thehead types of engines. As a matter of fact, however, my other valveliftersare also well adapted for use in conjunction with rocker armtypes of valve There is shown'a rocker arm 52 of standard form adaptedto actuate a valve 63 loaded or closed by its .spring 64. The latterparts are broken away inasmuch as they are not necessary greater portionof the load being carried on the wedges. Inasmuch as the valve stemelongation is slow and gradual, it follows that enough oil leaks out ofthe chamber 60 during the slow expansion ofthe valve stem 6 toaccommodate its increased length. The valve loading spring 8 is Vofsumcient strength to always bring 4the engine valve head 5 to its seat 4by keeping the volume of oil in the chamber 60 reduced to `a point justwhere the valve 5 will seat, but no further reduc- 'tioxr can beeffected inasmuch as the self-adjustlng. spring 58 always keeps 'theplunger-like wedges outwardly disposed, limited only byengagement of thewedge 5 9 against the valve The spaced reference lines XY 'show thevariation in lengthand range of change in both the valve stem and theautomatic tappet, and graphically shows the proportionately greatertravel of the compensating plungers as compared to the lesser change 'inlength of the valve stem 5.

The restricted size or small volume of the hydraulic chamber 460 incomparison to the available supply of oil in the large non-drain reforan understanding of Athis hydraulic form of valve lifter, and in factthe rocker arm 62 is merelyshown for the purpose of bringing out thegeneral purpose of an unusually long push rod 65 which is subject toconsiderable variation in length resulting from temperature changesv dueto its considerable length required to reach from the cam shaft in theengine up to the rocker arm on the cylinder head. A valve lifter ortappet guide 61 is carried by the enginein the usual way and in whichthe lifter or tappet sleeve reciprocates, and a cam shaft is providedwith a cam having a lobe Bland heel B9. The automatic self-adjustingvalve lifter constituting the invention is maintained in lio-clearanceengagement with and between the push rod 65 and cam means 68,59. Theupper end of the guide 61 is flared or cupped to collect oil from thesplash or other lubricating system of the engine to feed oil downwardlyto supply the hydraulic self-adjuster unit.

A valve lifter sleeve 10 is constructed similar to those heretoforedescribed and has vits lower of apertures 13 which pierce the wall ofthe sleeve.

The grooved and apertured sleeve 10 is adapted to reciprocate in thetappetguide 61 and the passages v4feedoil to the inside lower end of thesleeve where thel oil is available tolow into a ceptacle 48, incombination with the complete closing movement of the compensatingplungers 51 acting till they meet at the apex of the pilot wedge 5!causing displacement of the air from `the chamber 60 on the first turnof the cam lobe lli, produces a hydraulic valve lifter of dependablevand unfailing performance. Since the air is ex-y pelled from the chamber60 before the latter is primed with oil,l and only a small amount of oilis required, it .follows that there can exist only the slightest amountof occluded air or gas bubbles in the oil sucked into the small air-freecompressionchamber to be subsequently liberated bypressure and heat.Consequently air troubles hydraulic lifting chamber to compensate forcontracting and expansion of the push rod 65 and other parts of theengine or mechanism.

A wedge retainer or seat is provided for holding the self-adjustingmembers in place and comprises a cylindrically shaped plug-like member14 similar to that already explained Ain Figures 5 and 9. It has a ilatbottom seat 15 at the lower part of and within spaced parallelupstanding walls 16 defining a deep channel to movably carry aself-adjusting wedge set or pair as will be explained. This wedge guide14 is also grooved vertically and horizontally on its cylindrical andbottom surfaces, as indicated at 11, by which to -feed oil from .thesleeve holes 13 down underneath thereof and up through an oil inlet andpast a ball valve seat 1B and thence into a small volume hydrauliclifting compensating oil chamber 19 (see Figure 14) formed withinV itswalls 1e.

closes the oil inlet 18 Which is thus valve controlled to admit oil intothe chamber 19 formed by a set of interfitting self-adjusting wedgemeans -and also by the walls 16 of the wedge seat as will be described.The ball 8| is free in the opening 18 and closes by its own weight or bythe pressure of oil thereon.

A pair of automatically compensating interiltting wedges B2 and 83 areoperatively mounted in the channel 16. The wedge 82 is adapted asanunderneath member and undergoes slidable adjusting movement along theilat face 15 across the valved inlet 18 and transversely of the push rod85 and its line of thrust from the cam lobe E8. The upper wedge 88rundergoes a resultant adjustment travel in the sleeve 18 at rightangles y to the movement of the lower wedge 82 and hence axially inrespect to the push rod 85 to maintain a no-clearance engagement withthe latter. symmetrically engaging complementary faces 80 inclined tothe axis of the push rod 65 and which slidably iit together with aliquid tight seal. They also have parallel vertical ilat faces 84delining two of the walls of the hydraulic chamber 18 heretoforementioned. In fact, the two wedges have a pair of coacting angular planefaces 88, disposed in staggered relation, the

aforementioned vertical faces 84 serving to step or stagger saidwedgefaces 80 in spaced planes on each plunger-like member.

Each wedge 82 and 8 3 is made with a spring receiving socket l5 adaptedto receive an expanding compensating spring 88, the Iends of which forceoutwardly to'continuously urge or slide the wedge 82 laterally or alongits seat 15 transversely to the upper wedge 83 and thereby impartlongitudinal movement to the latter in the sleeve 1l. The lower wedge 82is made with an enlarged port opening 81 to pass oil from the valvecontrolled passage 18 up into the hydraulic chamber 19. The port 81 issumciently large to fully expose the ball valve 8l for all positions ofthe self-adjusting wedge 82 along its seat 15.

The wedge means with its valve and spring assembly just described ismounted within the v rounded lower end oi' the push rod 85 'and theself-adjusting spring. 88 acts to keep `the upper wedge snugly againstsaid push rod at all times.

The hydraulic valve lifter assembly, comprising the sleeve and itsself-contained compensating means per se. is mounted in the tappet guideI1 with the cam follower end 1I resting against the cam and the lowerend of the push rod 85 resting at 88 against the self-adjusting wedgeassembly. As soon as eil ls received into the -chamber'l, the entiremechanism assumes s3.

self-adjusted zio-clearance working engagement between all parts, fromthe valve Ss all ther-*Jay thru the mechanism back to the carri e9. The

first few revolutions of the cam lobe 68 will serve to/pump or suck oilfrom the supply passages "i2- and '11 up past the ball 8i and into thevchamber, lil to positively hold thewedge means 32 and apart in theirself attained and adjusted position. In the push rod 65 and other partsThe two wedge means 82 and 88 havel result of which is to work or adjustit to the left thereby lowering the upper wedge 83.to accommodate forsaid increased length of ythe push rod 65 and other parts, as caused bya rise in operating temperature vof the engine. Under great pressure ofthe .engine valve spring E4,l the adjacent hat faces 84 of the wedgemeans are ,gradually brought together by forcing the oil to leak outpast the plunger-like wedges and around 'the four walls defining thehydraulic lift and self-adjusting chamber 19. While the novel plungermeans 82, 83 npossesses an oil tight slid-- ing t'within the channelledchamber 16, the oil will nevertheless slowly escape in the minutequantity required during the considerable period that the push rodmechanism is expanding the few thousandths oi' an inch. y

On the other hand, iet usassume that the push rod 85. and relatedoperating parts contract or shorten up due to a drop in engine and valvetemperature, as in Figure 14 at the pointer X. Under this condition, theslight Aplay or clearance, which tends to show up between the cam 88 andits follower 1I vor between the rocker arm 82 and valve 68 or at 88,results in quick responsive action from the compressed spring 86 tospread the parallel wedge faces 84 apart, by sliding the wedge 82 to theright and the other wedge 88 upwardly to fill the space and follow thereceding push rod 65.' This operation results in sucking oil up throughthe inlet 18 to fill the` increased size chamber 18 and hydraulicallylocking the self-adjusted wedge 82 apart in spaced relation from thelongitudinally movable wedge 88, and the latter wedgeA is unyieldinglyheld to its push rod seat 88.

Inasmuch -as the engaged wedges' 82 and 83 carry the greater portion ofthe load or thrust required to compress the spring B4 and actuate itsvalve 63, it follows that very little pressure is exerted on the oilchamber 18 between the wedge faces 84. This reduces the tendency of theoil to escape from the chamber 18 during normal operation in actuatingthe engine valve u against its spring s4 since the 011 is canes upon todo little work. Furthermore, this reduction in pressure avoids oildeterioration and emulsiflcation. Also it is not necessary to soaccurately and finely grind the plunger wedges and their retaining walls15 and 16 inasmuch as there exists ayminimum pressure tending to forcetheoil to escape.

The angular relation to the horizontal, as

'defined by the adjusting inclined planes 80 of the wedges provides anincreased ratio of movement for the laterally adjustable wedge 82, ascompared to the lesser change in length of the push rod and other partsof the valve mechanism due to temperature variations and wear betweenthe parts. This latter function of amplified selfadiustment facilitatesthe priming of the hydraulic chamber 18, `and renders sensitive the ballvalve di by causing it to quickly unseat and admit a large volume oi'oil as compared to the extremely small change in length of the push rod55 and other parts. The compensating out stroke' ci' the wedge B2, i.e., its oil suction intake strokef'may be designed to be manythousanclths of an inch greater than the variation in length of theoperating meezianism, and tlnsdesign is with a number attained byemploying substantially the angle 80 shown von the wedge plungermembers. Hence the intake of oil is more denite and certain,

and larger increments of oil are drawn into the chamber 19, than wouldoccur withV an ordinary piston and cylinder type of hydraulic valvelifter.

engine valve 9| rests with zero clearance when the valve 89 is seated.'I'he upper face of the head |04, as well as the lower or adjacent faceof The small volume compression chamber 19 means that this form of thetappet operates on a .restricted amount of oil to hydraulically lockapart the self-adjusting plungers 82 and 83. Consequently little or noentrapped or occluded air is present in the oil drawn into said chamberwhich itself is free of air, at the instant of priming. inasmuch as thevplungers have the maximum displacement function, due to the ability ofthe plungers to close up, on the rst turn of the engine or cam, andthusforce out all air preliminary to the priming action.

The fourth form of construction in Figureszo 19 thru 23 This form of theinvention represents a sim- A Y pliiled construction of the hydraulicvalve lifter and employs a somewhat different form of selfadjustingwedge and 'hydraulic lit-ting chamber from thatrheretofore explained.There are provided two interfitting complementary wedge members havingin veiect screw-like jaw means, one of which is self-adjusting by reasonof executing a characteristic combined rotary and longitudinal Vmovementin lthe tappet sleeve to compensating chambers. In this forni,V there isa single adjustingV member which executes both motions necessary toadjust by the increased travel ratio principle of my invention. V

A .conventional valve head .89 operates in relation to its sea-t 90 andhas a stem 9| adapted to reciprocate in avalve stem guide- 92 under theclosing force of anY engine valve spring 93. The lower or tail end ofthevalve stem 9| is seated in no-clearance engagement with the hydraulicself-adjusting unit carried within a tappet or lifter sleeve 94 whichreciprocates within a guide 95 ordinarily formed in the engine crankcase where it cancollect oilin its flared receiving neck from the splashin the crank case or other engine lubricating system. The sleeve 94 hasa lower cam follower end 96 which bears with noclearance engagement on acam including a heel 91 and operating-lobe 98. These parts are in effectexemplary of standard practice, and a description will now be given ofthe automatic hydraulic compensating meanscarried in the reclprocating`lifter sleeve 94.

The cylindrical sleeve 94 constitutes a housing forthe compensatingmechanism and is made cylindrical head |04 with a supporting neck |05made with an oily inlet and ball valve sea-t |00 l and groovedrout at|01 in itsbottom for passing oil from;` the sleeve receptacle |I| upinto.L the neck |05. The memberl04 has its-counterpart in a. twin wedge.head |l3 having an upunder the automatic self-adjusting means th'erein.l Y A lowermost stationary wedge member has a..

Vthe cylindrical Wedge' H3, is formed with twol oppositely disposedinclined wedge or` spiral planes |08,` each of which extends 180 degreesaround the engaged or adjacent circular face of both heads 04 and H3.The twosymmetrical wedge faces |08 are not unlike a screw having a halfrevolution thread means. Each end. of s Y both inclined planes |08terminates in a vertical shoulder means |09 which is pierced or drilledat ||0 to form a springV receiving socket. When tted Atogether theshoulders |09 operate like jaws rwith acloslng and opening motion.

The""pluglike"membery |04 rests in the lower end ofthe lifter sleeve 94and has an oil tight nt between its cylindrical surface and the insideof'said sleeve, and the mem-ber ||3 likewise has an oil tight rotary andlongitudinal vmotion 'fit in the sleeve and is adapted to undergo thatmotion by reason of its coaction with the lower member |04. The angle ofthe spiral plane or planes |08 is chosen as heretofore explained inconnection with other forms of the invention. It'is desired that theangle |08 be steep enough to-initiate down rotary motion of the head ||3when pressure of the engine valve spring 93 is applied thereto. The neck|05 supports the wedge head |04above the cam follower end 96 I9 andprevents its escape therefrom. A pair of compensating springs `aremounted between the adjacent shoulders |09 with the ends of said springsinserted in the spring seats or sockets ||0 p and the expansive force of,the springs impress a pf external longitudinal oil rotative force onthe self-adjusting member I3. The assembly just described comprises theselfadjusting unit which is mounted in the sleeve 94. The two springs -I|1 are under compression and both expand to screw the head I9 relativelyon the stationary head |04 thereby forcing it upwardly to maintain thethrusting stem I4 in noclearance engagement with the engine valve stem9|.

The self-adjusting unit is so manufactured as to normally set theadjacent shoulders |09 in a mid-spaced relation with room for rotativeselfadjustment of the part ||3 in either direction so that it may screwup or down on the lower wedge |04 and inthe sleeve 94. The two sets ofspaced jaws 09 in partset off and form a restricted size hydraulic'chamber means ||9 ywhich has its formation completed Iby the inside wallof the sleeve. The compensating springs tend to screw the stem ||4upwardly to accommodate a contracting or shortening valve stem 9| butyield or compress under the greater. force of the engine valve spring 93to force the self-adjusting head |I3y A.rotatively downward tocompensate for elongation of the valve stem 9|. It is significant vthatthe inside cylindrical surface of the sleeve 94 closes .in and completesthe formation of the-two hydraulic lift chambers I9 (seeFigure 23) whichconnect radially with the valve controlled oil pas? sage in the neck|05. The volume of the chamber or chambers I9 increases and draws inmore oil as the thrust stem 4 screws out or upward and decreases andforces its oil out by seepage as the self-adjusting member I I3 rotatesin or downward. Oil Within the chamber I I9 locks or holds the jaws |09apart in their spaced adjusted position. v

In operation, should the compensating wedges |04 and ||3 be' assembledin a dry state without oil, the first few turns of the cam lobe'99 willycause oil to be pumped upwardly past the ball valve III into thetwo-part or radially formed hydraulic chamber. means II9 by reason ofthe combined rotative and longitudinal screwing movement of the doublefaced wedge head I I3 in the lifter sleeve 94. In other words, if thechamber' I Il is dry, the engine valve spring 93 forces the head II3 toscrew downwardly, while thelighter compensating springs |I1 impart areverse movement to the member II3, and thus a spiral pumping actionoccurs between the selfadjusting member ||3 and its stationary matingpart |04 during rotation of the cam. In this way, oil issucked fromthereceptacle III in the bottom of the sleeve 94 up into the chambers I I9to positively hold the spaced shoulders |09 apart by reason of the4non-coxnpressible oil body-in the chamber ||9,`and the self-adjustingunit is thus -rigidly set up to perform its function of opening theengine valve against the resistance and load of the heavy spring 93.

l the oil is forced by leakage out from the radial chamber II9 to thuscompensate for theincrease in length of any parts in the valvemechanism. The pointers vXY are shown spaced apart to a somewhatexaggerated degree to indicate the range of length variation in thevalve operating mechanism and consequently show the range of expansionand contracting in the tappet.'

The compression chamber II9 is of comparatively low volumetric capacityand hence it i'evquites little oil to hydraulically lock apart therelatively rotatable shoulders |09. Furthermore,

' the pair of shoulders |09v are adapted to coact or close up as shownin Figure 21, on the first half turn of the cam 99, and thus -bycomplete displacement or elimination of the chamber II9,

expel the air therefrom. The small measure of oil which now enters thisair-free chamber, on

the second half turn of the cam, functions satsistically different instructure, and the self-ad- Justing wedges d o not form the hydrauliclifting chamber.

An engine valve |2I is closed by its spring |22 ,it in place.

heel I 29, the combination hydro-mechanical lifter being interposedbetween the cam and valve stem and reciprocating in the usual form oftappet guidel21. l;

Ifl'he component parts of -this comblhation hydraulic and mechanicalvalve lifter are shown `in Figure 24 and include a sleeve I 29 asheretofore described and having external oil grooves |30 I connecting'with apertures I3I piercing the sleeve wall to lead oil from the upperend of the cylindrical guide |21 down into the sleeve |29 to supply olto the self-adjusting unit housed within thesleeve.

A cylinder-like tube |33 is grooved in its bottom at |34 and rests onthe'inside bottom end of the sleeve |29 together with a flange |35 atthe upper end of the cylinder |33 which holds This ilange is pierced at|36 to admit air -to the bottom of the sleeve |29 to 'equalize the airpressure therein so that oil will flow freely from the sleeve passagesI3| down into 4the -`bottom of the sleeve. The cylinder |33 isstationary on the bottom of the sleeve and the flange |35 braces itvertically in place. An oil inlet is made thru the bottom of thecylinder |33 and has an upper ball valve seat |31 to convey oil from thesleeve |29 up into this small compensating cylinder.

A ball check valve |39 closes the seat |31 and is freely movablethereon. The ball closes the oil opening |31 by its own weight, or bythe pressure of oil thereabove, or by virtue of the rapid up-movement ofthe sleeve |29. It is to be noted that this ball valve, like othersheretofore explained, is not spring actuated and hence is sensitive tothe slightest suction or intake tendency to draw oil upwardly thru theopening |31. A` resilient compensating spring |40 is placed-in thebottom end of the cylinder |33 and away from or concentrically with theball valve |39 so that there is no interference in function between thisspring and the ball.

A self-adjusting plunger or piston |42 has an upper at portion or guide|43 which terminatesin a wedge face |44. This piston is reciprocable inthe cylinder |33 against the coiled compression spring |40 and thespring continuously urges ythe piston upward in the cylinder to pressits wedge face |44, against a self-adjusting wedge nc'w described andhaving a similar face desig-l 'nated by the same number.

a guide slotl |41 cut inwardly from the longer on its seat |23 in -theusual way and is carried in a standard form of guide |24. The enginevalve is actuated by a cam having a lobe |25 and vice.

cylindrical surface of this transverselyslidable wedge |45. In fact theslot |41 defines the inner wedge face |44 for both wedge members |43 andI 45. The two wedge faces |44 coact to'perform a part of theself-adjusting function of this de- The upper face of the transverselymovable self-adjusting wedge |45 terminates in an inclined plane or wedging surface M3 which also denotes and defines the angle on a valvethrusti mg plug member iil mounted in the top end of the sleeve to closeit.

The aforementioned valve thrusting member |50 has its lower .face M8 asthe counterpart of the upper face formed on the self-adjusting member|45. This cylindrical plug-like member 50 slidably fits into the upperend of the tappet temperature of the engine is rising with the resultsleeve |29 to enclose all the parts therein and to also act as a thrustseat for the engine valve The self-adjusting three-element wedge means,

.together with the cylinder |33, as well as the spring |40 and ball |39,are assembled. as the compensator or self-adjusting unit" Within the'valve lifter sleeve |29 to complete its organization. The completeddevice is now mounted in the tappet guide |2`| as shown andthe expansiveforce of the spring means |40 immediately sets the multiple wedge means|43, |45 and |50 up in operative relation and snugly engages the thrustplug |50 against the tail end-of the valve stem |2|. In assembling theparts, oil may as well be poured in the sleeve |29 or into the cylinder|33 under its piston |42, but in any event the rst few turns of the camlobe |25 will act to suck oil past the ball valve |39 until .thecylinder |33 is full and no more oil can be drawn thereinto, whereuponthe piston |43 attains a selfadjusted stationary `position ready tostand rigid and lift the spring loaded engine valve |2I. If the cylinder|33 is dry when the parts are assembled the coacting Wedge faces |44 and|48 set up a long stroke reciprocation of the piston |42 which instantlyprimes this automatic tappet by filling the chamber under the piston.

In operation, the oil under the piston y|42`is ncncompressible andserves to brace and hold the piston in stationary position as the camlobev |25 lifts `the sleeve |23 to actuate the valve |2|` off its seat|23 against the powerful closing action of the engine valve spring |22.forms of the invention already described, the

that heretofore describedwith the exception that oil must new find itsway by leakage from under the piston |42. A little oil may escape pastthe ball |33 and possibly more oil will escape up pastV the piston |42because the-superior expansive force of the heavy engine valve spring|22 will under all circumstances keep the piston |42 sufficientlydownward, with the oil driven from underneath thereof, to always permitthe engine valve |2| to softly but positively close on its seat |23. Thepowerful engine valve spring |22, if the valve is not reaching its seat|23, enforces a right hand creeping movement ofthe self-adjusting wedge|45, and continues to do so as long as the valve stem |2| is expanding.The angular faces |44 and |48' are designed to set up va. laterallyright hand creeping motion, in the views being described, with aresultant downward creeping motion of the piston |42, in event thesuperior pressure ofthe spring |22 is applied to the plug |50 and thisof course happens when the valve stem |2| increases innitesimally thesli'ghest amount.

As in other coacting angular Wedge faces |44 and |43 in the presentinstance act to transmit substantially all or at least the greaterportion of the thrust from the lobe |25 upwardly to compress the spring|22A and open the valve, and the wedging means diminishes the load andpressure on the oil Within the cylinder |33 under the piston |42. Thebody of oil under the self-adjusting piston |42 is called upon toperform little work and is not whipped and emulsied to lose its`non-compressible characteristics as indeed would occur if all the camand engine valve spring pressure load was applied to the oil. e

In event the valve stem |2| contracts or shortens, as in Figure 25 atthe reference line X, space tends to 'develop between the endof thevalve stern |2I andthe thrust plug |50, but so soon as that occurs thespring |4|ly urges the piston |42 upwardly, causing the at wedgingmember |43 to creep upwardly in the slotl |'41 thereby urging theself-adjusting member |45 to the left along Elongation of the valvestern 2|- occurs so slowly and gradually that the high speed rotation ofthe cam and lobe |25 aids by vibration the extremely small creepingmovement of the plunger- |42 downwardly and the self-adjusting wedge |45to the right, but the non-compressible oil body under the piston rigidlyvholds the latter in non-yielding and thrusting position. In this way,the auto` matic self-adjusting unit yields, shortens up, or draws intoits sleeve |29, in precisely the same and exact proportion and at thesame rate as the valve stem |2I expands.

General explanation principles of the invention Several types ofmultiple wedge instrumentalities and sensitive hydraulic chambers havenow been described in a number of representative examples of myinvention. It is clear therefore that I have combined, into an operativeassembly, Y

both mechanical and hydraulic means, and do not rely solely on either totransmit the throw and, load of the cam to the engine valve to actuateit under4 the loading force of its spring. The design of. the severalexamples presented .herewith affords a thrust mechanism which carriesthe y load mechanically, resort being had tothe hyits flange seat |35.This operation causes the ,occurs when the engine `temperature drops.Thus the compensating spring |40 and the multiple wedge means,comprising the three parts |42, 45

.and |50, all coact to automatically self-adjust and maintain a positivestate of zero clearance from the valve seat |23 itself right down to therunning face 'of the cam |23. l

On the other hand, let us nowiassume that the that the valve stem l2 I`is gradually'elongating or growing in length,` as'in Figure26 at Y. Themode of self-adjustment is simply the reverse of -draulic oil body tosimply maintain the self-adjusting elements in place. While the many ad.vantages of this combination hydro-mechanical valve lifter have beenexplained in -connection with eachlexample shown, I will summarize themodes of operation and other pointswhich are conclusively instructive. y

For example, the parts, constituting my automatic tappets, are small insize and the tappet is light in weight. Light weight reciprocating partsare essential for high speed. Since little working pressure need beapplied to any of the hydraulic I chambers. the latter may besmall witha consequent small body'of oil therein` which contributes to reductionin weight of the reciprocating mass.

The filling of the hydraulic chambers is positive and instantaneous dueto the long suction stroke or travel of the load carrying self-adjustingplunger means. .This characteristic long stroke compensation, for thecorresponding short change in length of the train of mechanism toactuate the engine valve, is attained by the inclined planes or wedgefaces shown by which to greatly increase the motion in theself-adjusting load carrying unit over the shorter distance traveled bythe valvestem or pushl rod variation. Thev valve lifter yand itscompensating unit possess unusual rigidity to non-yieldingly transmitthe cam throw pressure for the reason that there exists no likelihood ofthe oil in the hy-' draulic chamber losing its non-compressiblecharacter. The small measure of oil used in the compression chamber isnot whipped and pounded by the heavy engine valve spring from onedirection and the high speed cam from the other directionY Consequently,no air bubbles are admixed in the oil to emulsify-and soften it.Furthermore, Aand even so, such a condition would not adversely affectthe rigidity and operation of the self-adjusting units because theextremely light pressure exerted on. the oil body in the hydraulicchamber would be successfully resisted and held by a softened anddeteriorated oil mass. The displacement of the air from the hydraulicchamber,

at the instant of priming it, gives an air-free chamber to begin with,and it remains so. I Other advantages and characteristics will becomeapparent upon understanding the foregoing and the invention fills a needfelt for improvements in this field.

What is claimed is:

v l. Valve operating mechanism, comprisingin combination, a springloaded valve operable in relation to its seat, a cam having a lobe andheel, a lifter sleeve having a cam follower portion 'and interposedbetween the valve and cam,.self adjusting wedge means including a pairof spaced wedges and an overlapping wedge coacyting with said pair, aretainer guide mounted in the sleeve and inwhich the self adjustingwedge means are operatively seated, an oil chamber enclosed between thewedge means and retainer guide, aA

compensating spring interposed between the wedge pair and urging sameapart, anl oil supply in the sleeve and valve controlled inlet leadingto the oil chamber to admit the trap oil between th-e Wedge pair to holdthem in outwardly adjusted position, whereby the overlapping coactingwedges sustain the pressure and vcarry most of the load imposed by thecam and spring loaded valve during the open period thereof.

2. Valve operating mechanism, comprising in combination, a spring loadedengine valve operable in relation to its seat, a cam having a lobe andheel, a lifter sleeve having a cam follower end traversed by the cam.,la wedge retainer seat -and guide means mounted in the upper end of thesleeve, an oil supply receptacle formed by and within the lower end ofsaid sleeve, a valvel J other or yieldingly afford an approachingmovement to maintain the aforesaid no-clearance engagement, a thirdwedge adjustable longitudinally in the wedge retainer'seat and guidemeans and coacting with the wedge pair, a hydraulic compensating chamberformed between the wedge pair within the wedge retainer seat and guidemeans and enclosed by the bottom ofsaid third wedge and into which opensthe aforesaid valve controlled inlet means to lill the chamber with oiland hold the 'wedge pair apart, an oil intake and discharge provided inthe sleeve above the cam follower end thereof to keep the receptaclefull ofoil and to discharge oil downV the cam traverses the cam followerwith minimum pressure while the spring loaded engine valve is on itsseat by reason of the wedge pair being seated in the wedge retainer seatand guide means to thus take up the expansive .force of the compensatingspring and prevent the full force thereof from riding the follower onVthe cam heel to rest said cam while the engine valve is on its seat, andto enable oil from the receptacle aforesaid to reach the lightlyengaging cam heel and follower surfaces.

3. A valve lifter for use in connection with valves and operatingmechanisml therefor comprising, a dat seat carried bv the valve lifterand at an angle to the anis of the valve to be actuated, compensatingdevices including wedge means slidable -on the seat, additional wedgemeans engaging the first wedge means and adjusted axially of the valveby the action of the rst wedge means adjusting on its seat, and ahydraulic chamber cooperating with the compensating devices to xthewedge means in their adjusted position. A

4. A valve lifter for use in connection with valves and operatingmechanism therefor comprising, a flat seat carried by the valve lifter'and at an angle to the axis of the valve to be actuated, compensatingdevices including wedge means sldable on the seat, additional wedgemeans engaging the rst wedge means and ad justed axially of the valve bythe action o f the rst wedge means adjusting on its seat, and oil lockedby a hydraulic chamber disposed between the rst named wedge means andagainst which the pressure of the wedge means on the seat is sustainedto x the latter against displacement.

5. A self adjusting valve lifter comprising coacting wedge means havingtwo, pairs of complementary faces each pair dening an inclined plane atan angle to the axis of a valve to 'be actuated, a hydraulic chamberbetween the wedge means, and a valve controlled inlet and oil supe plymeans communicating with the hydraulic chamber to feed oil thereintobetween' the wedge means ras the latter adjustably moves in relation toeach-other.

6. A self adjusting valve lifter comprising coacting wedge means havin'gtwo pairs of comvplementary faces each pair defining an inclined planeat an angle tothe axis of a valve to be actuated, a hydraulic chamberbetween the wedge means,l a valve controlled inlet and oil supply meanscommunicating with the,hydraulic chamber to feed oil thereinto betweenthe wedge means as the latter -adjustably moves in relation to eachother; and spring means disposed within the hydraulic chamber, at anangle to the axis of said valve to be actuated, and each end of the,spring means engaging under pressure against .the Wedgemeans.

' 7. A self adjustingvalve lifter comprising coacting wedge means havingtwo pairs of com- Aplementary faces each pair defining an inclined

